In a recent post, ‘The Unbearable Lightness of Philosophy’, http://backreaction.blogspot.ca/2016/08/the-unbearable-lightness-of-philosophy.html?spref=tw, physicist Sabine Hossenfelder takes a stab at the physics-philosophy antagonism that seems to be on the upswing.  The piece has some interesting observations, and appears to be intended as something of a peacemaking exercise, but it contains two curious claims.  I want to comment briefly on each.

First, she notes that the philosopher of science Massimo Pigliucci has argued that philosophy of science doesn’t exist to advance the work of scientists; rather, as a branch of philosophy, it exists to advance philosophy; I agree.  Philosophy of science is philosophy, after all, and its main goals are philosophical understanding of the world, in this case, the workings and results of science.  Hossenfelder briefly dismisses this as follows: “Philosophy, hence, isn’t just useless, but it’s useless on purpose. I applaud. At least that means it has a purpose.”  This is very odd or, at least, tendentious since it basically assumes that the only real use that something could have is that of advancing science.  But what is the defence of that claim?  Hossenfelder offers none, but it would be interesting to see why it is the case that, for example, advancing justice, reducing poverty, increasing access to art, or sport, or whatever else, must ultimately be judged as useless simply because it is not in the service of advancing science.  Surely this has to be wrong: there are many useful purposes other than aiding scientists in their valuable – usually, anyway – work.  One of these may well be philosophical understanding.  Of course it is possible that philosophical understanding is useless, but it can hardly be assumed that this is so simply because it fails to address the questions that most interest working scientists. 

Secondly, she comments on an interesting article by Tim Maudlin, who defends the relevance of philosophy for science as a result of its attention to conceptual and logical detail, which can help us understand “what follows rom what” and, therefore, what a mathematical model means for our understanding of the natural world.  Attention to semantic and logical detail means that explanatory or theoretical gaps can be spotted and alternative proposals can be suggested for filling them; philosophy has an imaginative component to it that can help create new lines of thinking.  Again, I agree.  Hossenfelder replies: “If you want to know ‘what follows from what,’ as Maudlin writes, you have to convert language into mathematics and thereby remove the ambiguities. Unfortunately, philosophers never seem to take that step, hence physicists’ complaints that it’s just words.” 

Now this is a very curious reply for a variety of reasons.  Consider that the extent to which language and thought can be modeled mathematically is a very profound, interesting, and puzzling question that has occupied philosophers for centuries (think Pythagoras, Leibniz, Frege, and Russell, for a sample).  Indeed, the tradition that grew out of the work of Frege, Russell, and the early Wittgenstein, which came to be known as “analytic philosophy”, is largely founded on the idea that mathematical logic is the appropriate set of tools for modeling natural language.  Much philosophy since then has been the attempt to evaluate, critique, and advance this very project.  Philosophers such as David Lewis, Timothy Williamson, and Saul Kripke have helped us to understand the extent to which modal logic can model counterfactual and subjunctive reasoning.  Philosophers such as Arthur Prior and Michael Dummett helped us uncover the logic underlying temporal reasoning.  Philosophers such as Graham Priest and J. C. Beal have advanced our understanding of the relationship between non-standard logics and human reasoning in a variety of arenas.  And so on, and so on. 

Rather than giving us reason to turn away from philosophy as useless, this response of Hossenfelder’s seems, rather, to give us plenty of reason to expose ourselves to philosophical work of the past 100 years or so and to continue the project of formalizing ordinary language and thought.  The attempt to employ formal systems to model everyday thinking and speaking is the attempt to make such thought and language mathematically precise.  Many recent and contemporary philosophers are engaged in precisely this project which, if successful, could represent a significant rapprochement between philosophy and science.  In short: successful, formal models of language could be the contact point between philosophy – and other disciplines, such as linguistics – on the one hand, and math and science, on the other.  That is, I think, a worthy project to pursue and one that has shown much promise. 

However, despite the precursors in Pythagoras and Leibniz, “formal philosophy” in its current incarnation is still relatively young, just over 100 years old.  There remains a great deal to be explored and uncovered.  There is even more work to be done in connecting formal models of language and thought to mathematical models of the physical world.  So I think Hossenfelder is wrong to suggest that philosophers never take this step; they often do.  It is just that the work is still in its relative infancy, often disputed, and needs concentrated effort to continue.  I also think, further, that she and other physicists are wrong to suppose that this is all “just words”: language is the medium by which we express and understand ourselves; understanding it correctly is of vital importance.  The philosophers I mention above, and others, are not playing with language in any trivial sense; they are working to understand it, with as close to mathematical precision as is possible.  If anything, they are working to advance the interests that Hossenfelder is expressing.

So, I think that a proper understanding of this branch of philosophy should, if anything, bring the physicists and philosophers closer together.